Eric and Erin are on a walk one evening when they come upon a lighted sign far way s in teh distance.

Eric and Erin are on a walk one evening when they come upon a lighted sign far way s in teh distance. ERic wants to read the sign, however he has forgotten his glasses which correct for nearsightedness. Erin is carrying a diverging lens in her pocket with focal length f. How far from Eric's eyes should she hold the lens for him to observe a clear focused image of the sign?